[Therapeutic management of postoperatively diagnosed bilateral recurrent laryngeal nerve paralysis]

Bilateral vocal cord paralysis is a rare but potentially dangerous postoperative complication in thyroid gland surgery. There is a controversial discussion about therapeutic management of postoperative bilateral vocal cord paralysis.

We analysed the frequency of bilateral nerve palsy in 985 operations. The disease of thyroid gland, the operative procedure, the exposure of laryngeal nerve, the mobility of vocal cord detected by an otolaryngologist, clinical symptoms and therapy of patients with bilateral paralysis were analysed. All patients were examined immediately postoperatively and 5 days, 14 days, 6 and 12 months after resection.

The overall transient bilateral palsy rate was 0.7%, the permanent 0.3%. The palsy rate depended on the disease of thyroid gland. After resection of simple goitre we found a 0.2% transient injury rate (0.1% permanent), after operation of thyroid cancer 2.0% transient (1.0% permanent) and in cases of recurrent goitre 5.9% transient (1.9% permanent) palsies. The immediate postoperative symptoms are also very different. There are patients suffering from stridor and dyspnoea, patients with dysphonia without dyspnoea and those without any symptoms. These different clinical symptoms are due to the different grade of laryngeal nerve damage and the resulting position of vocal cords. The bilateral paralysis was completely temporary in 4 cases. 12 months later 4 patients suffered from dysphonia. Only in 3 patients with thyroid cancer and a preoperative unilateral vocal cord paralysis tracheostomy was necessary after operation. The vocal cord mobility did not recover in these 3 cases after 12 months and the patients are not decannulated.

Bilateral paralysis is only relevant in thyroid cancer and recurrent goitre. The symptoms varies and no patient should leave the hospital without examination of the vocal cords by an otolaryngologist. Because vocal cord paralysis is temporary in most cases an emergency tracheostomy is seldom indicated.